<template>
  <div>
      <input ref='test' id="test">
      <button @click='diyfun'>Click</button>
  </div>
</template>
<script>
import {myfun} from '../js/test.js' //注意路徑
export default {
  data () {
    return {
      testvalue: ''
    }
  },
  methods:{
      diyfun:function(){
          myfun();
      }
  }
}
</script>

test.js代碼：

function myfun() {
console.log('Success')
}
export { //很關鍵
  myfun
}